When employing an electrically actuated valve assembly to control exhaust gas recirculation, the actuator should be isolated from the exhaust gases to assure proper operation. Electrically actuated valve assemblies heretofore proposed for controlling exhaust gas recirculation have not isolated the actuator from the exhaust gases in a practical manner.
This invention provides a practical electrically actuated exhaust gas recirculation valve assembly in which the actuator is isolated from the exhaust gases to assure proper operation.
In a preferred embodiment of an exhaust gas recirculation valve assembly employing this invention, a valve member controls the flow of exhaust gases from an exhaust gas chamber through a calibrated valve seat. A solenoid coil is located outside the chamber, and the valve member has a valve stem extending to a solenoid armature surrounded by the coil. The valve stem is surrounded by a pair of spring-biased seals that seal the openings around the valve stem into the solenoid coil and the chamber, and the armature-valve member-seal subassembly floats laterally to compensate for potential misalignment between the solenoid coil and the outlet.
The details as well as other features and advantages of three embodiments of this invention are set forth in the remainder of the specification and are shown in the drawing.